///The reason that the failure to forecast the Wenchuan M8.0 earthquake is studied based on systematically collecting the seismicity anomalies and their analysis results from the yearly earthquake tendency forecasts between the 2001 west Kunlunshan M8.1 earthquake and the 2008 Wenchuan M8.0 earthquake. The results show that after the 2001 west Kunlunshan 8.1 earthquake, the earthquake tendency estimation for Mainland China was that strong earthquakes are in active stage and strong earthquakes of magnitude 8 were anticipated, but the phenomena that many large earthquake occurred around Mainland China.